A Study of Nemtabrutinib vs Chemoimmunotherapy for Participants With Previously Untreated Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) Without TP53 Aberrations (MK-1026-008, BELLWAVE-008)

Researchers are looking for new ways to treat people with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). CLL and SLL are types of blood cancer. Researchers want to know if people who take nemtabrutinib compared to those who take the standard treatments in this study will live longer without their cancer growing, spreading or returning (progression free survival).

The main inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * Confirmed diagnosis of chronic lymphocytic leukemia (CLL)/ small lymphocytic lymphoma (SLL) and active disease clearly documented to have a need to initiate therapy * Has previously untreated CLL/SLL participants without tumor protein 53 (TP53) aberrations and documented 11q status and immunoglobulin heavy chain gene (IGHV) mutational status * The ability to swallow and retain oral medication Exclusion Criteria: * Has active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection * Has gastrointestinal dysfunction that may affect drug absorption (eg, gastric bypass surgery, gastrectomy) * Has known additional malignancy that is progressing or has required active treatment within the past 3 years, except basal cell carcinoma of skin, squamous cell carcinoma of skin, or carcinoma in situ (eg, breast carcinoma, cervical cancer in situ) that have undergone potential curative therapy * Has history of severe bleeding disorders * Has not adequately recovered from major surgery or has ongoing surgical complications